There's a strong moralistic undercurrent in the Strike series. Exploring some similar themes as The Casual Vacancy, there's no patience for people who are lazy, greedy, gossipy, fame-seeking, cheating, or deceitful.

Someone think of the cheaters!

Among others, she presents unlikeable characters who take the form of conservative, hypocritical politicians; radical leftists; wealthy elite who rub elbows with royalty; publishers, editors, authors—especially the misogynist ones—in the literary world; and journalists, particularly those who work for the Daily Mail and Sun chasing salacious stories and hacking phones.

So, her villians come from various backgrounds and political leanings? This is "moralistic" how?

By contrast, protagonist Cormoran Strike is an impoverished, disabled veteran who lost half a leg to an IED in Afghanistan. As a private detective, he serves as the sometimes caustic voice of reason as he seeks justice for his clients.

Oh no, a selfemployed PI who doesn't live like Magnum. If JKR would have made the protagonist a wealthy millionaire who does his work out of pure altrusim, she would have found that wrong, too.

Trans writer Katelyn Burns wrote for Them in 2018 that "[i]t’s an entirely common though insulting trope about trans women—that they are aggressive and unable to overcome their masculine nature, not to mention villainous—that has become all too common from cisgender authors with only a passing knowledge of trans people."

We all can read twitter and other places where TRAs congregate, we've seen their violent reactions to feminists irl. TRA gaslighting.

There are similarities in the language, like, "People have died trying to do it themselves," and one of the characters proudly announcing, "It's a need...I've known ever since I was a child. I'm in the wrong body. I need to be paralyzed."

That is what people with BIID are saying. Should JKR make just something up? And then piss off BIID-sufferers?

TL;DR: Handmaiden ties her brain into knots to justify the hatred of TRAs towards JKR.